hipHostRegister and hipHostMalloc refactor.

Note hipHostMalloc (not hipHostAlloc or hipMallocHost).
 -  the hipHost* is used for all HIP APIs dealing with Host memory.
    (including hipHostMalloc, hipHostFree, hipHostRegister,
hipHostUnregister, hipHostGetFlags, hipHostGetDevicePointer).
  - hipMallocHost is consistent with "hipMalloc" for allocating device
    memory.  Enumerations hipHostMalloc* also used as optional
    flags parm to hipHostMalloc.

tests/src/hipPointerAttrib.cpp

@@ -115,7 +115,7 @@ void testSimple()
     hipError_t e;
 
     HIPCHECK ( hipMalloc(&A_d, Nbytes) );
-    HIPCHECK ( hipHostAlloc((void**)&A_Pinned_h, Nbytes, hipHostAllocDefault) );
+    HIPCHECK ( hipHostMalloc((void**)&A_Pinned_h, Nbytes, hipHostMallocDefault) );
     A_OSAlloc_h = (char*)malloc(Nbytes);
 
     size_t free, total;
@@ -168,7 +168,7 @@ void testSimple()
 
 
     // Device-visible host memory
-    printf ("\nDevice-visible host memory (hipHostAlloc)\n");
+    printf ("\nDevice-visible host memory (hipHostMalloc)\n");
     HIPCHECK( hipPointerGetAttributes(&attribs, A_Pinned_h));
     printf("getAttr:%-20s", "A_pinned_h"); printAttribs(&attribs);
 
@@ -283,7 +283,7 @@ void clusterAllocs(int numAllocs, size_t minSize, size_t maxSize)
             reference[i]._attrib.hostPointer   = NULL;
             reference[i]._attrib.allocationFlags = 0; // TODO-randomize these.
         } else {
-            HIPCHECK(hipHostAlloc((void**)&ptr, reference[i]._sizeBytes, hipHostAllocDefault));
+            HIPCHECK(hipHostMalloc((void**)&ptr, reference[i]._sizeBytes, hipHostMallocDefault));
             reference[i]._attrib.memoryType    = hipMemoryTypeHost;
             reference[i]._attrib.devicePointer = ptr;
             reference[i]._attrib.hostPointer   = ptr;